Question

Explain why NaBH4 is less reactive than LiAlH4 (Hint: write the structure of each ion, (BH4) - and (AlH4) - , with their formal charges

Answer 1

Answer:

See explanation

Explanation:

The ability of a hydride to act as a reducing agent depends on the electro negativity of the central atom in the complex hydride anion.

If we compare the electronegativities of Boron and Aluminum, Boron is more electronegative than aluminum. The more electronegative the central atom is, the lesser the electron density on the hydride and the lesser its ability to act as a reducing agent.

For the reason stated above, LiAlH4, having aluminium of low electro negativity as its central atom is a better reducing agent than NaBH4.